In U.S. Pat. No. 3,291,947, issued Dec. 13, 1966, to Roswell C. Van Sickle, entitled "Interrupting Structures For Compressed-Gas Circuit-Interrupters Having Double-Break Hollow Rotative Moving Contact-Arm Assembly", and assigned to the assignee of the instant application, there is illustrated and described an improved high-power compressed-gas circuit-interrupter in which a double-break rotating contact-arm construction is used, and wherein two closing resistances are inserted into the circuit for each module during the closing operation to thereby damp voltage surges occurring on the connected transmission line. During the opening operation of the circuit-breaker, however, such closing resistances are not inserted into the circuit, and have no function whatsoever as set forth in said patent. A movable resistor contact, interposed in the path of the closing movement of the rotatable cross-arm, electrically connects the two closing resistances into the circuit during the closing operation prior in point of time to the subsequent closing of the two main moving contacts associated with the main rotatable cross-arm assembly.
Former supporting constructions of the closing resistance have been cumbersome, and have employed heavy insulating straps, which are somewhat susceptible to voltage breakdown, and thereby tend to limit the voltage breakdown capability of the interrupter during the closing operation while the resistor is inserted into the circuit.